Troubleshoot the "Secure Connection Failed" error message

If Firefox can't access a secure site (one that starts with https:) you will see an error page with the heading, Secure Connection Failed, and a message about the error. This article will describe some of these error messages.

Certificate warnings

Firefox uses certificates on secure websites to ensure that your information is being sent to the intended recipient and can't be read by eavesdroppers.

Certificate will not be valid until (date)

(site name) uses an invalid security certificate. The certificate is not trusted because the issuer certificate has expired. The certificate will not be valid until (date). (Error code: sec_error_expired_issuer_certificate)

This error can occur if your computer clock has the wrong date, in which case the date given in the error message will be in the past. To fix the problem, set your system clock to today's date and time (double-click the clock icon on the Windows Taskbar).

Certificate is only valid for (site name)

This error is telling you that the certificate sent to you by the site is actually for another site. While anything you send would be safe from eavesdroppers, the recipient may not be who you think it is.

A common situation is when the certificate is actually for a different part of the same site. For example, you may have visited https://example.com, but the certificate is for https://www.example.com. In this case, if you access https://www.example.com directly, you should not receive the warning.

The certificate is not trusted because the issuer certificate is unknown

(site name) uses an invalid security certificate. The certificate is not trusted because the issuer certificate is unknown.
(Error code: sec_error_unknown_issuer)

The file cert8.db in your profile folder may have become corrupted. Delete this file while Firefox is closed.

Open your profile folder:

At the top of the Firefox window, click on the Firefox button, go over to the Help menuOn the menu bar, click on the Help menuAt the top of the Firefox window, click on the Help menu and select Troubleshooting Information. The Troubleshooting Information tab will open.Click the menu button
, click help
and select Troubleshooting Information. The Troubleshooting Information tab will open.

Under the Application Basics section, click on Show FolderShow in FinderOpen Directory. A window with your profile filesfolder will open.

At the top of the Firefox window, click on the Firefox button and then select ExitAt the top of the Firefox window, click on the File menu and then select ExitOn the menu bar, click on the Firefox menu and select Quit FirefoxAt the top of the Firefox window, click on the File menu and select Quit

Click the menu button
and then click ExitQuit

Click on the file named cert8.db.

Press command+Delete.

Restart Firefox.

cert8.db will be recreated when you restart Firefox. This is normal.

The certificate is not trusted because no issuer chain was provided

(site name) uses an invalid security certificate. The certificate is not trusted because no issuer chain was provided.
(Error code: sec_error_unknown_issuer)

You may have enabled SSL scanning in your security software such as ESET or BitDefender. Try to disable this option.

The certificate is not trusted because it is self signed

(site name) uses an invalid security certificate. The certificate is not trusted because it is self signed. (Error code: sec_error_untrusted_issuer)

or

(site name) uses an invalid security certificate. The certificate is not trusted because it is self signed. (Error code: sec_error_ca_cert_invalid)

Self-signed certificates make your data safe from eavesdroppers, but say nothing about who the recipient of the data is. This is common for intranet websites that aren't available publicly.

The certificate contains the same serial number as another certificate

Your certificate contains the same serial number as another certificate issued by the certificate authority. Please get a new certificate containing a unique serial number. (Error code: sec_error_reused_issuer_and_serial)

This error alerts you to the fact that the certificate the page you're visiting uses has a serial number identical to one you've already accepted. This warning cannot be bypassed using the method below. For more information and for instructions on how to work around this message, see the Certificate contains the same serial number as another certificate article.

The OCSP server has no status for the certificate

An error occurred during a connection to (site name). The OCSP server has no status for the certificate. (Error code: sec_error_ocsp_unknown_cert)

Bypassing the warning

You can tell Firefox to bypass these certificate warnings. You should only bypass the warning if you're sure that the site is legitimate. Legitimate public sites will not ask you to do this. An invalid certificate can be an indication of a web page that will defraud you or steal your identity.